Earlier this month, Director of National Intelligence Dan Coats backtracked on a promise to disclose how many Americans’ communications have been swept up in warrantless mass surveillance of foreign targets. In fact, Coats admitted that even “Herculean” efforts by the NSA would be unable to the determine the number, which Reuters reports“could be in the millions.”

This is not just an American concern. States around the world are increasingly policing internet activities. Online surveillance is now common among governments and companies alike. Recently, for instance, my colleagues at the Citizen Lab, located at the University of Toronto’s Munk School of Global Affairs, revealed in a report that the Mexican government has used surveillance spyware to track and monitor Mexican journalists, human rights lawyers, and activists. And cyberbullying and harassment are on the rise, too.

Read more on Slate. Jon Penney goes to report on research he conducted on this important topic, and you’ll want to read his findings.